Burkitt Lymphoma Essay
Burkitt Lymphoma was mapped out in geographic distribution across Africa by Dr. Denis Parsons Burkitt (Huang 2005). This disease is a high grade B-cell neoplasm, which has two major forms: the endemic (i. e. African nature) and the non-endemic (i. e. sporadic nature). Burkitt Lymphoma is mainly found as childhood tumor, yet it is, also, observed in adult patients (Huang 2005). This Lymphoma type is one of the fastest growing malignancies in humans, and it has a high growth fraction (Huang 2005).
Burkitt Lymphoma is a monoclonal proliferation of B lymphocytes that is characterized by small non-cleaved cells is appeared to be uniform in appearance (Huang 2005). It produces a diffuse pattern of tissue involvement. While under the microscope, this lymphoma is characterized by the presence of a “starry sky” appearance due to scattered macrophages with phagocyte cell debris; this is observed in other highly proliferate lymphomas, as well (Huang 2005).
The African form of this lymphoma most often involves the maxilla or mandible and the involvement of abdominal organs, for instance the kidneys, ovaries, and retroperitoneal structures, but is somewhat less common (Huang 2005). On the contrary, the sporadic form involves the abdominal organs: distal ileum, cecum, and mesentery. The involvement of pelvic organs or facial bones is rare (Huang 2005).
The majority of Burkitt Lymphomas carry a translation of the c-myc oncogene from chromosome eight to the immunoglobulin (lg) heavy-chain region on chromosome fourteen (t 8;14)or a light-chain loci chromosome two (t 8;2)or chromosome twenty-two (t 8;22) (Huang 2005). Within the African form of Burkitt Lymphoma, The Epstein-Barr virus (EBV) has been implicated strongly and the relationship in the sporadic form is less clear (Huang 2005). Epstein-Barr virus is associated in approximately twenty percent of sporadic cases. The rare cases in adult are usually associated with immunodeficiency, predominantly AIDS, respectively (Huang 2005).
Some have reasoned, the host is unable to generate adequate T-lymphocyte response or Epstein-Barr specific cytoxic T-cells (Huang 2005). This subsequently results in excessive B cell proliferation. The lymphocytes have receptors especially for the Epstein-Barr virus and are the specific targets (Huang 2005). In the African form, the hosts are believed to be unable to increase a suitable immune response to primary Epstein-Barr infection. This is possible due to coexistent malaria or other infections that are immunosuppressive, also (Huang 2005).
Burkitt Lymphoma is an extremely rare cancer in the United States, with only 100 new cases each year. However, Burkitt Lymphoma is endemic in many regions of equatorial Africa and other tropical regions between latitudes 10° south and 10° north. The frequency of this cancer in these endemic regions is 100 per million children (Huang 2005). The male-to-female ratio is 2-3:1, and the most common a in children is seven years of age is the mean in African, eleven years of age is the current mean outside of Africa (Huang 2005). Prior to aggressive therapeutic treatment program, children with Burkitt Lymphoma died rapidly.
However, with a combination of chemotherapy and CNS prophylaxis the survival rate has increase to at least sixty percent; and patients with a limited disease now have a ninety percent chance of survival (Huang 2005). Patients with bone marrow and CNS involvement have a poor prognosis. Adults with the disease, especially those in the advanced stage, do more poorly than affected children (Huang 2005). In the African form, patients most often present swelling of the mandible and other facial bone with the loosening of teeth, and swelling of the lymph nodes, which have rapid growth below the mandible (Huang 2005).
Patients who have the sporadic form are commonly presented with abdominal tumors that cause swelling and pain in the affected area; few patients have symptoms of bowel obstruction that is caused by tumor growth (Huang 2005). Burkitt tumors growth is tremendously rapid in nature, and patients have evident metabolic derangement and renal function impairment and may include epidural mass, skin nodules, central nervous system symptoms, and bone marrow involvement (Huang 2005). Rare cases of Burkitt lymphoma can present acute leukemia with fever, anemia, bleeding, and adenopathy (Huang 2005).
Foremost indicators of Burkitt Lymphoma include soft tissue mass associated with involvement of the mandible, enlarged cervical lymph nodes, abdominal masses, and ascites (Huang 2005). Moreover, the exact cause and mechanisms of this lymphoma are presently unknown. It is important that Burkitt Lymphoma is distinguished from other abdominal tumors in childhood, such as Wilms tumor, neuroblastoma, and peripheral neuroectodermal tumor (Huang 2005). Also, within the bone marrow, B and T precursors and myeloid leukemia must be distinguished (Huang 2005).
Systemic chemotherapy is the treatment for this lymphoma is all its stages. The survival rate ultimately depends on the stage at initial diagnosis (Huang 2005). Patients with a localized infection respond well to chemotherapy, with an excellent rate of survival. Cyclophosphamide therapy has been curative for eighty percent of children in Africa with the early stage of Burkitt Lymphoma (Brock 1996). The effect of cyclophosphamide is due to its metabolite phosphoramide mustard (Brock 1996). The metabolite is only formed in cells which have low levels of aldehyde dehydrogenase.
The Phosphoramide mustard forms DNA cross links between and within DNA strands — this leads to cell death (Brock 1996). However, combination chemotherapy has improved treatment results. Intensive, short-duration, alkylator-based regimens are necessary for all patients with the sporadic form (Huang 2005). In patients with AIDS, Burkitt Lymphoma is in advanced stage at time of diganosis and tends to involve extranodal sites (Huang 2005). Furthermore, because of underlying immunodeficiency and leukopenia, these patients tolerate systemic chemotherapy very poorly.
A patient’s expiration usually follows shortly after diagnosis (Huang 2005). A nine week regiment of cyclophosphamide, doxorubicin, vincristine, and prednisone was effective for early stages of the disease and a longer regimen included a combination with radiation (Link et al. 1997). The cure rate more than exceeded ninety percent with minimal toxicity. Therefore, a lesser-intensive therapy is under evaluation as a potentially effective means to steer clear of unnecessary toxicity for patients with early stages (Link et al. 1997).
This may achieve similar cure rates obtained with prolonged treatment (Link et al. 1997). Vanderbilt Medical Center has reported results for patients with poor-prognosis non-Hodgkin Lymphoma, which includes Burkitt Lymphoma, using a high dose and short-duration combined chemotherapy comprising cyclophosphamide, etoposide, doxorubicin, vincristine, bleomycin, methotrexate with leucovorin rescue, prednisone (Huang 2005). Burkitt Lymphoma patients have a high risk of tumor lysis syndrome before chemotherapy is started because of rapid tumor cell turnover (Huang 2005).
This is a life-threatening situation and should be anticipated and addressed to the patient prior to beginning treatment (Huang 2005). Treatment should be preformed at a proper facility with renal dialysis is available, predominantly for patients with progression of disease (Huang 2005). Treatment of recurrent Burkitt lymphoma is difficult. Bone marrow transplantation is the only hope of long-term survival for these patients (Huang 2005). Burkitt Lymphoma is a high grade B-cell neoplasm, which is highly endemic in Central Africa and sporadic throughout other countries (Huang 2005). This disease is the fastest growing malignancy in children.
A combination chemotherapy is the most effect mode of treatment and has high cure rates within early stages, and the moderate cure rates for progressed patients (Huang 2005). References Brock N. (1996). The history of the oxazaphosphorine cytostatics. Cancer. 78:542-7. Link MP, Shuster JJ, Donaldson SS, et al. (1997). Treatment of children and young adults with early-stage non-Hodgkin’s lymphoma. New England Journal of Medicine. 30 October 1997; 337(18): 1259-66. Huang, H, MD, PhD et al.. (2005). Burkitt Lymphoma. eMedicine. Date visited 19 April 2006. http://www. emedicine. com/med/topic256. htm